The Nested Model Approach

The eSA-Marine system uses a nested model approach where now-cast/forecast oceanic information is telescoped down though 3 grid scales:

  • 10 km global Ocean MAPS model
  • 2.5 km Southern Australian Regional Ocean Model (SAROM)
  • 500 m Two Gulfs Model (TGM).

The Southern Australian Regional Ocean Model serves 2 purposes:

  1. Display now-cast/forecast information for the southern shelves.
  2. Provide open boundary information to resolve features within the Two Gulfs Model.

The Ocean MAPS and SAROM models improve now-cast/forecast accuracy through 'data assimilation' of real time data on temperature, salinity and sea level height. The system uses the globally adopted Climate Forecast System Reanalysis.

Both SAROM and TGM models:

  • are forced with:
    • best atmospheric now-cast/forecast (ACCESS-R) data available from the BoM, including; heating, evaporation, winds, atmospheric pressure.
    • major tides from the global model TPX08.
  • use the hydrodynamic open source Regional Ocean Modelling System (ROMS) with 30 levels in the vertical.

The TGM uses 680 X 790 cells in the horizontal and takes much longer to run. SAROM uses 439 X 270 cells.

The model runs and data assimilation takes several hours to update the animations and maps on this site. As a result this may show now-cast information that is several hours old.

The flow of information from the global 10 km grid OceanMAPS, to the 2.5 km SAROM and then 500 m grid TGM is illustrated below.

Diagram showing the flow of information from the global10 km grid OceanMAPS, to the 2.5 km SAROM and then 500 m grid TGM.
Diagram showing the flow of information from the global10 km grid OceanMAPS, to the 2.5 km SAROM and then 500 m grid TGM.

Disclaimer

This is a research and experimental product and no liability is assumed for the use of the eSA-Marine system or its products including now-casts and forecasts. In particular, this includes all conditions outlined in the general PIRSA disclaimer that can be accessed here or at the bottom of this page. Moreover, other sources of ocean now-cast/forecasts and or data may not align or be consistent with output from the eSA-Marine System which may be in error and/or out of date. Users should obtain their own independent advice. No liability is assumed for the eSA-Marine products presented here.

Page Last Reviewed: 11 Jan 2017
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